• Kinetics and mechanism of the reversible formation of the binuclear species between pyridine-2-carboxylato (pentaammine) cobalt(III) and cobalt(II) in aqueous solution

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      https://www.ias.ac.in/article/fulltext/jcsc/105/04-05/0245-0252

    • Keywords

       

      Kinetics; binuclear species; coordinated picolinate; cobalt(II)

    • Abstract

       

      The kinetics of formation and dissociation of the binuclear complex of cobalt(II) with pyridine-2-carboxylato(pentaammine) cobalt(III) have been studied in the temperature range 10–25°C and atI=0·3 mol dm−3 (ClO4. The formation of (NH3)5CoO2CC5H4NCo4+ in thepH range 2·35–3·20 involves the reaction of Co(OH2)62+ with the protonated (pyridine-N) and the deprotonated forms of the complex. The rate and activation parameters for the formation reaction are consistent with anId mechanism. The binuclear species undergoes dissociation to yield the parent cobalt(III) substrate and cobalt(II) via spontaneous and acid-catalysed paths. The rate data at 20°C for the spontaneous dissociation of the binuclear complex and of mono(pyridine-2-carboxylato) cobalt(II) are comparable indicating the chelating nature of the binuclear species.

    • Author Affiliations

       

      Nigamananda Das1

      1. Regional Research Laboratory, Bhubaneswar - 751 013, India
    • Dates

       
  • Journal of Chemical Sciences | News

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